Devices and methods for targeted delivery of a substance
A device for applying a bubble of a substance to a tissue surface, the device comprising a cannula, a distal tip at the distal end portion of the cannula, the distal tip having a bubble support surface and an exit port extending through the bubble support surface, an expansion fluid passageway extending through the cannula to the exit port, a source of an expansion fluid and an actuator therefor. In some arrangements, the distal tip can be configured to support a layer of the substance thereon over the distal port and the device can be configured such that the advancement of the expansion fluid from the fluid source through the exit port causes at least one bubble of the substance to form on the distal tip, wherein the at least a portion of the bubble can be transferred to the tissue surface to treat a defect on the tissue surface.
1. A method of repairing a defect in a retinal tissue, comprising:
advancing a substance supply device having a cannula and a distal tip toward the defect;
providing a layer of a bioadhesive substance over an exit port in the distal tip of the device;
forming a bubble of the bioadhesive substance on the distal tip by advancing an expansion fluid through the exit port to the layer of bioadhesive substance, wherein the bubble is at least partially attached to the distal tip; and
transferring the bubble to the retinal tissue so as to at least partially cover the defect in the retinal tissue.
2. The method of claim 1 , further comprising transferring a plurality of bubbles of the bioadhesive substance to the defect.
3. The method of claim 2 , further comprising transferring a plurality of bubbles of the bioadhesive substance to retinal tissue adjacent to the defect.
4. The method of claim 1 , further comprising covering the defect with a patch, wherein transferring the bubble to the retinal tissue so as to at least partially cover the defect in the retinal tissue comprises transferring at least one bubble of the bioadhesive substance to a first surface of the patch and positioning the patch over the defect so that the first surface of the patch having the bioadhesive substance thereon is in contact with at least the retinal tissue adjacent to the defect.
5. The method of claim 1 , further comprising transferring a plurality of bubbles of the bioadhesive substance to retinal tissue adjacent to the defect.
6. The method of claim 1 , further comprising covering the defect with a patch.
7. The method of claim 1 , wherein the bubble comprises an approximately spherically shaped film of the bioadhesive substance enclosing the expansion fluid.
8. The method of claim 7 , wherein the film extends away from the distal tip.
9. The method of claim 1 , further comprising advancing the expansion fluid through an expansion fluid passageway in the cannula, the expansion fluid passageway being in fluid communication with the exit port.
10. The method of claim 9 , further comprising advancing the expansion fluid using an actuator.
11. The method of claim 10 , wherein the actuator is coupled to a source of expansion fluid.
12. The method of claim 9 , further comprising advancing the expansion fluid by compressing a bladder containing the expansion fluid.
13. The method of claim 9 , further comprising advancing the expansion fluid by moving a plunger.
14. The method of claim 1 , further comprising providing the layer of a bioadhesive substance through a substance supply channel in the cannula.
15. The method of claim 1 , wherein the expansion fluid comprises a gas.
16. The method of claim 1 , wherein the expansion fluid comprises a liquid.
17. The method of claim 1 , further comprising advancing the expansion fluid through an expansion fluid passageway in the cannula and providing the layer of a bioadhesive substance through a substance supply channel in the cannula.
18. The method of claim 17 , wherein the substance supply channel surrounds the expansion fluid passageway.
19. The method of claim 1 , further comprising advancing a substance supply channel for providing the bioadhesive substance through an expansion fluid passageway for providing the expansion fluid.
20. The method of claim 1 , wherein the expansion fluid is advanced through a lumen defined by the distal tip in fluid communication with the exit port.
21. The method of claim 20 , wherein the exit port has a diameter that is smaller than a diameter of the lumen.
22. The method of claim 1 , wherein the bubble is formed on a rim circumventing the exit port.
23. The method of claim 22 , wherein the rim extends from an outer surface of the distal tip inward relative to an inner surface of the distal tip.
24. The method of claim 22 , wherein the rim has a flat, circumferential face forming a distal most surface of the distal tip.
25. The method of claim 22 , further comprising supporting the layer of the bioadhesive substance on the rim.
26. The method of claim 22 , wherein the rim has a circumferential face oriented at an acute angle to a longitudinal axis of the distal tip.
27. The method of claim 1 , wherein the bioadhesive substance is provided through a bioadhesive pathway and the expansion fluid is advanced through a lumen defined by the distal tip in fluid communication with the exit port and separate from the bioadhesive pathway.
28. The method of claim 27 , wherein the bioadhesive pathway completely surrounds at least a portion of the lumen.
29. The method of claim 27 , further comprising directing flow of the bioadhesive substance radially inwardly.
30. The method of claim 1 , wherein the expansion fluid is advanced through a lumen defined by the distal tip in fluid communication with the exit port and the bubble is formed on a rim circumventing the exit port.
31. The method of claim 30 , wherein the rim has a flat face at a distal most surface of the distal tip, the exit port has a smaller diameter than the lumen, and the flat face extends inward from an outer surface into the lumen a distance greater than a thickness of a cannula wall adjacent the flat face.
32. A method of treating eye tissue, comprising:
advancing a distal region of a substance supply device having a cannula and a distal tip into the eye;
providing a layer of a bioadhesive substance over an exit port in the distal tip of the device;
forming a bubble of the bioadhesive substance on the distal tip by advancing an expansion fluid through the exit port to the layer of bioadhesive substance, wherein the bubble is at least partially attached to the distal tip; and
transferring the bubble to the eye tissue.
33. The method of claim 32 , wherein treating the eye tissue acts to block liberation of retinal pigment epithelium (RPE) cells to reduce proliferative vitreoretinopathy (PVR).
34. The method of claim 32 , wherein treating the eye tissue reduces proliferative vitreoretinopathy (PVR).
35. The method of claim 32 , further comprising transferring a plurality of bubbles of the bioadhesive substance to the eye tissue.
36. The method of claim 32 , further comprising covering the eye tissue with a patch, wherein transferring the bubble to the eye tissue comprises transferring at least one bubble of the bioadhesive substance to a first surface of the patch and positioning the patch so that the first surface of the patch having the bioadhesive substance thereon is in contact with the eye tissue.
37. The method of claim 32 , wherein the bubble comprises an approximately spherically shaped film of the bioadhesive substance enclosing the expansion fluid.
38. The method of claim 37 , wherein the film extends away from the distal tip.
39. The method of claim 32 , further comprising advancing the expansion fluid through an expansion fluid passageway in the cannula, the expansion fluid passageway being in fluid communication with the exit port.
40. The method of claim 39 , further comprising advancing the expansion fluid using an actuator.
41. The method of claim 40 , wherein the actuator is coupled to a source of expansion fluid.
42. The method of claim 39 , further comprising advancing the expansion fluid by compressing a bladder containing the expansion fluid.
43. The method of claim 39 , further comprising advancing the expansion fluid by moving a plunger.
44. The method of claim 32 , further comprising providing the layer of a bioadhesive substance through a substance supply channel in the cannula.
45. The method of claim 32 , wherein the expansion fluid comprises a gas.
46. The method of claim 32 , wherein the expansion fluid comprises a liquid.
47. The method of claim 32 , further comprising advancing the expansion fluid through an expansion fluid passageway in the cannula and providing the layer of a bioadhesive substance through a substance supply channel in the cannula.
48. The method of claim 47 , wherein the substance supply channel surrounds the expansion fluid passageway.
49. The method of claim 32 , further comprising advancing a substance supply channel for providing the bioadhesive substance through an expansion fluid passageway for providing the expansion fluid.
50. The method of claim 32 , wherein the expansion fluid is advanced through a lumen defined by the distal tip in fluid communication with the exit port.
51. The method of claim 50 , wherein the exit port has a diameter that is smaller than a diameter of the lumen.
52. The method of claim 32 , wherein the bubble is formed on a rim circumventing the exit port.
53. The method of claim 52 , wherein the rim extends from an outer surface of the distal tip inward relative to an inner surface of the distal tip.
54. The method of claim 52 , wherein the rim has a flat, circumferential face forming a distal most surface of the distal tip.
55. The method of claim 52 , further comprising supporting the layer of the bioadhesive substance on the rim.
56. The method of claim 52 , wherein the rim has a circumferential face oriented at an acute angle to a longitudinal axis of the distal tip.
57. The method of claim 32 , wherein the bioadhesive substance is provided through a bioadhesive pathway and the expansion fluid is advanced through a lumen defined by the distal tip in fluid communication with the exit port and separate from the bioadhesive pathway.
58. The method of claim 57 , wherein the bioadhesive pathway completely surrounds at least a portion of the lumen.
59. The method of claim 57 , further comprising directing flow of the bioadhesive substance radially inwardly.
60. The method of claim 32 , wherein the expansion fluid is advanced through a lumen defined by the distal tip in fluid communication with the exit port and the bubble is formed on a rim circumventing the exit port.
61. The method of claim 60 , wherein the rim has a flat face at a distal most surface of the distal tip, the exit port has a smaller diameter than the lumen, and the flat face extends inward from an outer surface into the lumen a distance greater than a thickness of a cannula wall adjacent the flat face.